Known hair cosmetics contain cationic surfactants such as mono- or di-straight and long chain alkyl quaternary ammonium salts or mono- or di-branched long chain alkyl quaternary ammonium salts in order to improve the texture of the hair. Recently, it has been attempted to use these cationic surfactants together with higher alcohols and fats and oils such as glycerides and liquid paraffin so as to further improve the texture of the hair.
However these known hair cosmetics are disadvantageous in that they give only unsatisfactory effects of improving the texture of the hair. Namely, they are poor in their conditioning effects (for example, softness, moist feel, smoothness, antielectrificating effect) on the hair. Although it has been attempted to add fats and/or oils to hair cosmetics to thereby improve the above-mentioned moist feel, the hair cosmetics thus obtained suffer from some problems, including stickiness and oily feel. These products show limited conditioning effects, in particular, under dry conditions. In addition, known hair cosmetics exert only a limited effect of protecting the hair from damage.
Accordingly, a demand has arisen in the art for a hair cosmetic exhibiting excellent conditioning effects (for example, moist feel) and which will also sufficiently protecting the hair from damage without showing any stickiness or having an oily feel.
Under these circumstances, we have conducted extensive studies in order to overcome the problems of the prior art. As a result, we have found that the combined use of a cationic surfactant with a specific dialkylene glycol monoalkyl ether makes it possible to protect the hair from damage caused by the swelling of the hair upon washing as the dialkylene glycol monoalkyl ether penetrates into the hair and is then adsorbed thereby. We have further found that the hair cosmetic thus obtained exerts excellent conditioning effects (for example, moist feel, softness, smoothness) on the hair without showing any stickiness or having an oily feel even under dry condition, owing to their humecting effect after penetrated into the hair. The present invention was achieved based on these findings.